Combustor with dilution openings

ABSTRACT

A gas turbine engine including a compressor section and a combustion section in serial flow arrangement along an engine centerline, the combustion section having a combustor liner, a dome wall coupled to the combustor liner, and a dome inlet located in the dome wall, a fuel injector fluidly coupled to the dome inlet, a combustion chamber fluidly coupled to the fuel injector and defined at least in part by the combustor liner and the dome wall, and at least one set of dilution openings located in the dome wall and fluidly coupled to the combustion chamber.

TECHNICAL FIELD

The present subject matter relates generally to a combustor withdilution openings, more specifically to a combustor having a set ofdilution openings located in a dome wall.

BACKGROUND

Turbine engines are driven by a flow of combustion gases passing throughthe engine to rotate a multitude of turbine blades. A combustor can beprovided within the gas turbine engine and is fluidly coupled with aturbine into which the combusted gases flow.

The use of hydrocarbon fuels in the combustor of a gas turbine engine isknown. Generally, air and fuel are fed to a combustion chamber, the airand fuel are mixed, and then the fuel is burned in the presence of theair to produce hot gas. The hot gas is then fed to a turbine where itcools and expands to produce power. By-products of the fuel combustiontypically include environmentally harmful toxins, such as nitrogen oxideand nitrogen dioxide (collectively called NO_(x)), CO, UHC (e.g.,methane and volatile organic compounds that contribute to the formationof atmospheric ozone), and other oxides, including oxides of sulfur(e.g., SO₂ and SO₃).

One solution to reducing the environmentally undesirable compounds is touse fuels other than hydrocarbons. Hydrogen or hydrogen mixed withanother element or compound can be used for combustion, however hydrogenor a hydrogen mixed fuel can result in a higher flame temperature thantraditional fuels. That is, hydrogen or a hydrogen mixed fuel typicallyhave a wider flammable range and a faster burning speed when compared totraditional fuels such petroleum-based fuels, or petroleum and syntheticfuel blends.

Standards stemming from air pollution concerns worldwide regulate theemission of oxides of nitrogen (NO_(x)), unburned hydrocarbons (UHC),and carbon monoxide (CO) generated as a result of the gas turbine engineoperation. In particular, nitrogen oxide (NO_(x)) is formed within thecombustor as a result of high combustor flame temperatures duringoperation. It is desirable to decrease NO_(x) emissions while stillmaintaining desirable efficiencies by regulating the profile and orpattern within the combustor.

BRIEF DESCRIPTION OF THE DRAWINGS

In the Drawings:

FIG. 1 is a schematic of a gas turbine engine.

FIG. 2 depicts a cross-section view along line II-II of FIG. 1 of acombustion section of the gas turbine engine.

FIG. 3 is a cross-sectional view of a combustor in the combustionsection formed from a combustor liner having multiple sets of dilutionopenings according to an aspect of the disclosure herein.

FIG. 4 is a schematic of a variation of a portion II having a first setof dilution openings for the combustor from FIG. 3 according to anaspect of the disclosure herein.

FIG. 5 is a variation of the first set of dilution openings from FIG. 3according to an aspect of the disclosure herein.

FIG. 6 is a variation of a portion III from FIG. 5 with a dome wallaccording to an aspect of the disclosure herein.

FIG. 7 is another variation of the portion III from FIG. 5 with a domewall according to another aspect of the disclosure herein.

FIG. 8 is a schematic of a variation of a portion IV from FIG. 3 with afirst set of dilution openings according to an aspect of the disclosureherein.

FIG. 9 is a schematic of a variation of the portion IV from FIG. 3 witha first set of dilution openings according to another aspect of thedisclosure herein.

FIG. 10 is a schematic of a variation of the portion IV from FIG. 3 witha first set of dilution openings according to an aspect of thedisclosure herein.

FIG. 11 is a schematic of a variation of the first set of dilutionopenings from FIG. 10 , also located in the region IV of FIG. 3 ,according to another aspect of the disclosure herein.

FIG. 12 is a schematic of a variation of the portion IV from FIG. 3 witha first set of dilution openings according to yet another aspect of thedisclosure herein.

FIG. 13 is a schematic of a variation a portion V of FIG. 3 with a flarecone and a dome wall according to an aspect of the disclosure herein.

FIG. 14 is a schematic of a variation the portion V of FIG. 3 with aflare cone and a dome wall according to another aspect of the disclosureherein.

FIG. 15 a variation of a portion of the cross-section view from FIG. 2according to another aspect of the disclosure herein.

FIG. 16 is a schematic of a variation of the combustion section fromFIG. 2 illustrating an arrangement of dome walls about the enginecenterline.

FIGS. 17-21 are a first, second, third, fourth, and fifth exemplarydistributions for any of the first set of dilution openings describedherein located within the dome walls as arranged in FIG. 16 .

DETAILED DESCRIPTION

Aspects of the disclosure described herein are directed to a combustor,and in particular a combustor liner having dilution openings. Forpurposes of illustration, the present disclosure will be described withrespect to a gas turbine engine. It will be understood, however, thataspects of the disclosure described herein are not so limited and that acombustor as described herein can be implemented in engines, includingbut not limited to turbojet, turboprop, turboshaft, and turbofanengines. Aspects of the disclosure discussed herein may have generalapplicability within non-aircraft engines having a combustor, such asother mobile applications and non-mobile industrial, commercial, andresidential applications.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any implementation described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other implementations. Additionally, unlessspecifically identified otherwise, all embodiments described hereinshould be considered exemplary.

As used herein, the terms “first”, “second”, and “third” may be usedinterchangeably to distinguish one component from another and are notintended to signify location or importance of the individual components.

The terms “forward” and “aft” refer to relative positions within a gasturbine engine or vehicle, and refer to the normal operational attitudeof the gas turbine engine or vehicle. For example, with regard to a gasturbine engine, forward refers to a position closer to an engine inletand aft refers to a position closer to an engine nozzle or exhaust.

As used herein, the term “upstream” refers to a direction that isopposite the fluid flow direction, and the term “downstream” refers to adirection that is in the same direction as the fluid flow. The term“fore” or “forward” means in front of something and “aft” or “rearward”means behind something. For example, when used in terms of fluid flow,fore/forward can mean upstream and aft/rearward can mean downstream.

The term “fluid” may be a gas or a liquid. The term “fluidcommunication” means that a fluid is capable of making the connectionbetween the areas specified.

Additionally, as used herein, the terms “radial” or “radially” refer toa direction away from a common center. For example, in the overallcontext of a gas turbine engine, radial refers to a direction along aray extending between a center longitudinal axis of the engine and anouter engine circumference.

All directional references (e.g., radial, axial, proximal, distal,upper, lower, upward, downward, left, right, lateral, front, back, top,bottom, above, below, vertical, horizontal, clockwise, counterclockwise,upstream, downstream, forward, aft, etc.) are only used foridentification purposes to aid the reader's understanding of the presentdisclosure, and do not create limitations, particularly as to theposition, orientation, or use of aspects of the disclosure describedherein. Connection references (e.g., attached, coupled, connected, andjoined) are to be construed broadly and can include intermediatestructural elements between a collection of elements and relativemovement between elements unless otherwise indicated. As such,connection references do not necessarily infer that two elements aredirectly connected and in fixed relation to one another. The exemplarydrawings are for purposes of illustration only and the dimensions,positions, order and relative sizes reflected in the drawings attachedhereto can vary.

The singular forms “a”, “an”, and “the” include plural references unlessthe context clearly dictates otherwise. Furthermore, as used herein, theterm “set” or a “set” of elements can be any number of elements,including only one.

Approximating language, as used herein throughout the specification andclaims, is applied to modify any quantitative representation that couldpermissibly vary without resulting in a change in the basic function towhich it is related. Accordingly, a value modified by a term or terms,such as “about”, “approximately”, “generally”, and “substantially”, arenot to be limited to the precise value specified. In at least someinstances, the approximating language may correspond to the precision ofan instrument for measuring the value, or the precision of the methodsor machines for constructing or manufacturing the components and/orsystems. In at least some instances, the approximating language maycorrespond to the precision of an instrument for measuring the value, orthe precision of the methods or machines for constructing ormanufacturing the components and/or systems. For example, theapproximating language may refer to being within a 1, 2, 4, 5, 10, 15,or 20 percent margin in either individual values, range(s) of valuesand/or endpoints defining range(s) of values. Here and throughout thespecification and claims, range limitations are combined andinterchanged, such ranges are identified and include all the sub-rangescontained therein unless context or language indicates otherwise. Forexample, all ranges disclosed herein are inclusive of the endpoints, andthe endpoints are independently combinable with each other.

FIG. 1 is a schematic view of a gas turbine engine 10. As a non-limitingexample, the gas turbine engine 10 can be used within an aircraft. Thegas turbine engine 10 can include, at least, a compressor section 12, acombustion section 14, and a turbine section 16 in serial flowarrangement. A drive shaft 18 rotationally couples the compressor andturbine sections 12, 16, such that rotation of one affects the rotationof the other, and defines a rotational axis or engine centerline 21 forthe gas turbine engine 10.

The compressor section 12 can include a low-pressure (LP) compressor 22,and a high-pressure (HP) compressor 24 serially fluidly coupled to oneanother. The turbine section 16 can include an LP turbine 26, and an HPturbine 28 serially fluidly coupled to one another. The drive shaft 18can operatively couple the LP compressor 22, the HP compressor 24, theLP turbine 26 and the HP turbine 28 together. Alternatively, the driveshaft 18 can include an LP drive shaft (not illustrated) and an HP driveshaft (not illustrated). The LP drive shaft can couple the LP compressor22 to the LP turbine 26, and the HP drive shaft can couple the HPcompressor 24 to the HP turbine 28. An LP spool can be defined as thecombination of the LP compressor 22, the LP turbine 26, and the LP driveshaft such that the rotation of the LP turbine 26 can apply a drivingforce to the LP drive shaft, which in turn can rotate the LP compressor22. An HP spool can be defined as the combination of the HP compressor24, the HP turbine 28, and the HP drive shaft such that the rotation ofthe HP turbine 28 can apply a driving force to the HP drive shaft whichin turn can rotate the HP compressor 24.

The compressor section 12 can include a plurality of axially spacedstages. Each stage includes a set of circumferentially-spaced rotatingblades and a set of circumferentially-spaced stationary vanes. Thecompressor blades for a stage of the compressor section 12 can bemounted to a disk, which is mounted to the drive shaft 18. Each set ofblades for a given stage can have its own disk. The vanes of thecompressor section 12 can be mounted to a casing which can extendcircumferentially about the gas turbine engine 10. It will beappreciated that the representation of the compressor section 12 ismerely schematic and that there can be any number of stages. Further, itis contemplated, that there can be any other number of components withinthe compressor section 12.

Similar to the compressor section 12, the turbine section 16 can includea plurality of axially spaced stages, with each stage having a set ofcircumferentially-spaced, rotating blades and a set ofcircumferentially-spaced, stationary vanes. The turbine blades for astage of the turbine section 16 can be mounted to a disk which ismounted to the drive shaft 18. Each set of blades for a given stage canhave its own disk. The vanes of the turbine section can be mounted tothe casing in a circumferential manner. It is noted that there can beany number of blades, vanes and turbine stages as the illustratedturbine section is merely a schematic representation. Further, it iscontemplated, that there can be any other number of components withinthe turbine section 16.

The combustion section 14 can be provided serially between thecompressor section 12 and the turbine section 16. The combustion section14 can be fluidly coupled to at least a portion of the compressorsection 12 and the turbine section 16 such that the combustion section14 at least partially fluidly couples the compressor section 12 to theturbine section 16. As a non-limiting example, the combustion section 14can be fluidly coupled to the HP compressor 24 at an upstream end of thecombustion section 14 and to the HP turbine 28 at a downstream end ofthe combustion section 14.

During operation of the gas turbine engine 10, ambient or atmosphericair is drawn into the compressor section 12 via a fan (not illustrated)upstream of the compressor section 12, where the air is compresseddefining a pressurized air. The pressurized air can then flow into thecombustion section 14 where the pressurized air is mixed with fuel andignited, thereby generating combustion gases. Some work is extractedfrom these combustion gases by the HP turbine 28, which drives the HPcompressor 24. The combustion gases are discharged into the LP turbine26, which extracts additional work to drive the LP compressor 22, andthe exhaust gas is ultimately discharged from the gas turbine engine 10via an exhaust section (not illustrated) downstream of the turbinesection 16. The driving of the LP turbine 26 drives the LP spool torotate the fan (not illustrated) and the LP compressor 22. Thepressurized airflow and the combustion gases can together define aworking airflow that flows through the fan, compressor section 12,combustion section 14, and turbine section 16 of the gas turbine engine10.

FIG. 2 depicts a cross-section view of the combustion section 14 alongline II-II of FIG. 1 . The combustion section 14 can include an annulararrangement of fuel injectors 76 disposed around the engine centerline21 of the gas turbine engine 10. Each of the fuel injectors 76 can beconnected to a combustor 80. It should be appreciated that the annulararrangement of fuel injectors can be one or multiple fuel injectors andone or more of the fuel injectors 76 can have different characteristics.The combustor 80 can have a can, can-annular, or annular arrangementdepending on the type of engine in which the combustor 80 is located. Ina non-limiting example, an annular arrangement is illustrated anddisposed within a casing 78. The combustor 80 is defined by a combustorliner 82 including an outer annular combustor liner 82 a and an innerannular combustor liner 82 b concentric with respect to each other andannular about the engine centerline 21. A dome assembly 84 including adome wall 90 together with the combustor liner 82 can define acombustion chamber 86 annular about the engine centerline 21. A firstand second set of dilution openings 92, 93 can be located in the domewall 90. The first and second set of dilution opening 92, 93 can beannularly arranged about the engine centerline 21. The first and secondset of dilution openings 92, 93 can be annular dilution openingsdefining a continuous annulus about the engine centerline 21 asillustrated. At least one fuel injector 76, illustrated as multiple fuelinjectors annularly arranged about the engine centerline 21, is fluidlycoupled to the combustion chamber 86. A compressed air passageway 88 canbe defined at least in part by both the combustor liner 82 and thecasing 78.

FIG. 3 depicts a cross-section view taken along line of FIG. 1illustrating the combustion section 14. A third set of dilution openings94 can be located in the combustor liner 82, connecting the compressedair passageway 88 and the combustor 80.

The fuel injector 76 can be coupled to and disposed within the domeassembly 84 upstream of a flare cone 104 to define a fuel/air mixtureoutlet 96. The fuel/air mixture outlet can define a dome inlet 96 suchthat the fuel/air mixture outlet and dome inlet are one in the same andfluidly coupled to each other at the flare cone 104. The fuel injector76 can include a fuel inlet 98 that can be adapted to receive a flow offuel (F) and a linear fuel passageway 100 extending between the fuelinlet 98 and the fuel/air mixture outlet/dome inlet 96. The first set ofdilution openings 92 can define a swirler provided at the fuel/airmixture outlet/dome inlet 96 to swirl incoming compressed air (C) inproximity to fuel (F) exiting the fuel injector 76 and provide ahomogeneous mixture of air and fuel entering the combustor 80.

Both the inner and outer combustor liners 82 a, 82 b can have an outersurface 106 and an inner surface 108 at least partially defining thecombustion chamber 86. The combustor liner 82 can be made of onecontinuous monolithic portion or be multiple monolithic portionsassembled together to define the inner and outer combustor liners 82 a,82 b. By way of non-limiting example, the outer surface 106 can define afirst piece of the combustor liner 82 while the inner surface 108 candefine a second piece of the combustor liner 82 that when assembledtogether form the combustor liner 82. As described herein, the combustorliner 82 includes the third set of dilution openings 94. It is furthercontemplated that the combustor liner 82 can be any type of combustorliner 82, including but not limited to a double walled liner or a tileliner. An igniter 110 can be provided at the combustor liner 82 andfluidly coupled to the combustion chamber 86, at any location, by way ofnon-limiting example upstream of the third set of dilution openings 94.

During operation, compressed air (C) can flow from the compressorsection 72 to the combustor 80 through the dome assembly 84. The firstset of dilution openings 92 in the dome wall 90 allow passage of atleast a portion of the compressed air (C), the portion defining a firstdilution airflow (D1), from the dome assembly 84 to the combustionchamber 86.

Additionally, compressed air (C) can flow from the compressor section 72to the combustor 80 through the compressed air passageway 88. The thirdset of dilution openings 94 in the combustor liner 82 allow passage ofat least a portion of the compressed air (C), the portion defining asecond dilution airflow (D2), from the compressed air passageway 88 tothe combustion chamber 86.

Some compressed air (C) can be mixed with the fuel (F) and upon enteringthe combustor 80, the mixture is ignited within the combustion chamber86 by one or more igniters 110 to generate combustion gas (G). Thecombustion gas (G) is mixed using the dilution airflow (D1, D2) suppliedthrough the sets of dilution openings 92, 93, 94, and mixes within thecombustion chamber 86, after which the combustion gas (G) flows througha combustor outlet 112 and exits into the turbine section 74.

FIG. 4 is a schematic of a portion of a combustor 180, a variation ofthe combustor 80, according to another aspect of the disclosure herein.The combustor 180 is substantially similar to a portion III of combustor80, therefore, like parts will be identified with like numeralsincreased by 100. It should be understood that the description of thelike parts of the combustor 80 applies to the combustor 180 unlessotherwise noted.

The combustor 180 has a combustion chamber 186 that is defined by acombustor liner 182 and a dome assembly 184 including a dome wall 190. Aflare cone 204 can define a fuel/air mixture outlet/dome inlet 196 and adome centerline (DC) extending from a geometric center of the flare cone204. The dome centerline (DC) can be angled with respect to the enginecenterline 21 and extend in a direction substantially parallel to theengine centerline 21 (FIG. 2 ). The dome wall 190 can extend radiallyaway from the dome centerline (DC). A first and second set of dilutionopenings 192 a, 193 a can be located in the dome wall 190 between thefuel/air mixture outlet/dome inlet 196 and the combustor liner 182. Thefirst and second set of dilution openings 192 a, 193 a can extendbetween a dilution inlet 122 and a dilution outlet 124 and include atleast one vane 120 disposed between the dilution inlet 122 and thedilution outlet 124. In one aspect the first and second set of dilutionopenings 192 a, 193 a can be annular about the engine centerline 21forming concentric circles (FIG. 1 ) where the first set of dilutionopenings 192 a circumscribe the second set of dilution openings 193 a.There can be any number of vanes 120 oriented circumferentially aboutthe engine centerline 21. The at least one vane 120 can be an axial flowor a radial flow vane or a combination of an axial flow and a radialflow vane. An axial flow vane moves an airflow in an axial direction,along a primarily longitudinal axis extending parallel to the domecenterline (DC). A radial flow vane moves air in a radial direction,along a primarily vertical axis extending perpendicular to the domecenterline (DC). A pair of vanes 120 can define a nozzle having firstdilution centerline (CL1) angled toward the dome centerline (DC) of thecombustion chamber 186. The first dilution centerline (CL1) can make adilution angle (a) with the dome centerline (DC) that is less than 90°.In some implementations the dilution angle (a) can be less than or equalto 60°.

The dome wall 190 can extend approximately perpendicularly (within 5%)to the dome centerline (DC) from the flare cone 204 toward the outlet124 of the first set of dilution openings 192 to define a flat portion116. At least one cooling hole 126 can be located where the dome wall190 meets the combustion liner 182. The dome wall 190 between the outlet124 and the at least one cooling hole 126 can be angled toward thecombustion liner 182 away from the fuel/air mixture outlet/dome inlet196 to define a conic portion 114 with an obtuse angle (β) between thedome wall 190 and the combustion liner 182. The obtuse angle (β) isgreater than 90°. In some implementations the obtuse angle (β) can begreater than 130°. The conic portion 114 can meet the flat portion 116at a first junction 118. The flare cone 204 can meet the dome wall 190at a second junction 128.

During operation, the at least one vane 120 can provide a swirl flow(SF) to the combustion chamber 186. Additionally, the at least onecooling hole 126 can provide additional compressed air (C) for coolingan interior surface 208 of the combustion liner 182.

FIG. 5 is a schematic of the portion II of combustor 80 of FIG. 3 for avariation of combustor 180. A variation of the first and second set ofdilution openings 192 a, 193 a of FIG. 4 is illustrated as a first andsecond set of dilution openings 192 b, 193 b located in the dome wall190 between the fuel/air mixture outlet/dome inlet 196 and the combustorliner 182. In this variation a second dilution centerline (CL2) isangled away from the dome centerline (DC) of the combustion chamber 186.The second dilution centerline (CL2) can still make a dilution angle (a)with the dome wall 190 that is less than 90°. In some implementationsthe dilution angle (a) can be less than or equal to 60°. In thisparticular variation, however, the outlet 124 points towards thecombustor liner 182. Therefore, it should be understood, that thedilution angle (a) can vary between −60 and 60 degrees.

FIG. 6 illustrates a variation of the dome wall 190 according to anotheraspect of the disclosure herein, by way of non-limiting example in theregion III of FIG. 5 . A dome wall 190 a can be angled to define a conicportion 114 a around the outlet 124 of the first set of dilutionopenings 192 b. The dome wall 190 a can include a flat portion 116 aextending radially from the second junction 128. The first junction 118can define a beginning of the conic portion 114 a. The conic portion 114a can extend radially from the first junction 118 toward the combustorliner 182 to form the obtuse angle (β).

FIG. 7 illustrates another variation of the dome wall 190 according toanother aspect of the disclosure herein, by way of non-limiting examplein the region III of FIG. 5 . A dome wall 190 b can be angled to definea conic portion 114 b extending radially from the second junction 128toward the combustor liner 182 to form the obtuse angle (β). The firstjunction 118 can still be located between the outlet 124 and the end 128of the flare cone 204. The dome wall 190 b can include a flat portion116 b extending radially from the first junction 118 around the outlet124 of the first set of dilution openings 192 b.

While illustrated as having the same cross-section, it should beunderstood that the dome wall 190, 190 a, 190 b, the conic portion 114,114 a, 114 b, the flare cone 204 and any other portion of the domeassembly 184 can be formed of materially separate parts. By “meet”, theparts described herein simply overlap at the first and second junctions118, 128 described herein. While a junction can mean joined physicallytogether, it can also mean overlapping at that point in space.

FIG. 8 is a schematic of a first set of dilution openings 292 located,by way of non-limiting example in the region IV of FIG. 3 of combustor80. The first set of dilution openings 292 are substantially similar tothe first set of dilution openings 92, therefore, like parts will beidentified with like numerals increased by 200. It should be understoodthat the description of the like parts of the first set of dilutionopenings 92 applies to the first set of dilution openings 292 unlessotherwise noted.

A dome wall 290 can define a deflector 230 having two parts an innersection 230 a and an outer section 230 b. The outer section 230 b canhave a face 232 located axially forward of the inner section 230 a. Thefirst set of dilution openings 292 can be disposed between the inner andouter sections 230 a, 230 b. The first set of dilution openings caninclude multiple rows 234 of vanes 220 arranged radially with respect toeach other.

FIG. 9 is a schematic of a first set of dilution openings 392 located,by way of non-limiting example in the region IV of FIG. 3 of combustor80. The first set of dilution openings 392 are substantially similar tothe first set of dilution openings 92, therefore, like parts will beidentified with like numerals increased by 300. It should be understoodthat the description of the like parts of the first set of dilutionopenings 92 applies to the first set of dilution openings 392 unlessotherwise noted.

A dome wall 390 can define a deflector 330 having two parts an innersection 330 a and an outer section 330 b. The outer section 330 b canhave a face 332 located axially forward of the inner section 330 a. Thefirst set of dilution openings 392 can be disposed between the inner andouter sections 330 a, 330 b. An axially extending passage 340 defining athird dilution centerline (CL3) can terminate in an outlet 324 on thedeflector 330. The axially extending passage 340 can separate the innersection 330 a from the outer sections 330 b. The axially extendingpassage 340 can define at least one of the openings in the first set ofdilution openings 392. The axial extending passage 340 can include atleast one vane 320 disposed within the passage 340 proximate to theoutlet 324.

FIG. 10 is a schematic of a first set of dilution openings 492 alocated, by way of non-limiting example in the region IV of FIG. 3 ofcombustor 80. The first set of dilution openings 492 a are substantiallysimilar to the first set of dilution openings 92, therefore, like partswill be identified with like numerals increased by 400. It should beunderstood that the description of the like parts of the first set ofdilution openings 92 applies to the first set of dilution openings 492 aunless otherwise noted.

A dome wall 490 can define a deflector 430. The deflector 430 caninclude multiple axial deflectors 442, illustrated as two axialdeflectors. The axial deflectors 442 can extend axially away from thedome wall 490. The first set of dilution openings 492 a can include, byway of non-limiting example three dilution openings radially disposedand separated by the axial deflectors 442. In other words, the first setof dilution openings 492 a can be disposed within the dome wall 490 in astaggered relationship with the axial deflectors 442. Each of the firstset of dilution openings 492 a can be flush with the dome wall 490. Thefirst set of dilution openings 492 a can include at least one vane 420,or any number of vanes 420 oriented circumferentially about the flarecone 504. While illustrated as axial flow vanes 420 a, the at least onevane 420 can be axial or radial or a combination of axial and radialflow vanes.

A first axial deflector 442 a can extend axially downstream from thedome wall 490 a first distance (d1). A second axial deflector 442 b canbe located radially outward from the first axial deflector 442 a. Thesecond axial deflector 442 b can extend axially downstream from the domewall 490 a second distance (d2) where the second distance (d2) isgreater than the first distance (d1). A straight-line 444 connectingdistal ends of the first and second axial deflectors 442 a, 442 b can bedrawn to intersect with a combustor liner 482 to form an obtuse angle(β).

A third set of dilution openings 446 can be located around the flarecone 504. The third set of dilution openings 446 can include a purgepassage 448 extending between a purge inlet 450 and a purge outlet 452.An inlet plenum 454 can be fluidly coupled to the first set of dilutionopenings 492 a and the purge passage 448 at the purge inlet 450.

During operation compressed air (C) can flow through the first set ofdilution openings 492 a to form a dilution flow (DF). In someimplementations the flow through the first set of dilution openings 492a can form a swirl flow (SF). Any particles remaining in the inletplenum 454 can be removed via the third set of dilution openings 446 asa purged airflow (P). A fuel/air (F/C) mixture can flow along a pathillustrated by arrows 456. The purge flow (P) is further utilized forcooling of the flare cone 504 and to ensure that the fuel/air (F/C)mixture does not attach to a hot side of the dome wall 490. The pathillustrated by arrows 456 can be controlled by a combination of thedilution flow (DF), the swirl flow (SF) and the purged airflow (P).

FIG. 11 illustrates a variation of the first set of dilution openings492 a of FIG. 10 , numerically indicated as a first set of dilutionopenings 492 b located in the dome wall 490 between a fuel/air mixtureoutlet/dome inlet 496 and the combustor liner 482. Some part numbershave been removed for clarity.

The first set of dilution openings 492 b can be defined at least in partby at least one vane 420, or any number of vanes 420 orientedcircumferentially about the flare cone 504. The first set of dilutionopenings 492 b can include an inner opening 493 a, an outer opening 493c and a middle opening 493 b disposed between the inner and outeropenings 493 a, 493 c. The outer opening 493 c can be located proximatethe combustor liner 482 and include an axial flow vane 420 a.

A pair of radial flow vanes, a first and a second radial flow vane 420r, 421 r, can be disposed axially upstream of the dome wall 490 in fluidcommunication with the inlet plenum 454. A first axially extendingpassage 440 a can extend from a first dilution inlet 422 a at the firstradial flow vane 420 r to a first dilution outlet 424 a at the dome wall490. The first radial flow vane 420 r can extend from the first dilutioninlet 422 a radially inward, in a direction away from the combustorliner 482. While illustrated as extending radially inward, it should beunderstood that the first radial flow vane 420 r can extend radiallyoutward, or that both the first and second radial flow vanes 420 r, 421r can extend radially outward.

A second axially extending passage 440 b can extend from a seconddilution inlet 422 b at the second radial flow vane 421 r to a secondoutlet 424 b at the distal ends of the first and second axial deflectors442 a, 442 b. The second radial flow vane 421 r can extend from thesecond dilution inlet 422 b radially outward, in a direction toward thecombustor liner 482. While illustrated as extending radially outward, itshould be understood that the second radial flow vane 421 r can extendradially inward, or that both the first and second radial flow vanes 420r, 421 r can extend radially inward.

In addition to or along with the flow described previously herein,during operation compressed air (C) can travel through the first axialflow vane 420 a and exhaust proximate the combustor liner 482.Compressed air (C) proximate the fuel/air mixture outlet/dome inlet 496can be radially drawn into first axially extending passage 440 a by thefirst radial flow vane 420 r. The second radial flow vane 421 r canmirror the first radial flow vane 420 r by drawing compressed air (C)from proximate the combustor liner 482 into the second axially extendingpassage 440 b, or vice versa depending on the vane orientation. Theradial flow vanes 420 r, 421 r can be recessed from the dome wall 490 togive sufficient axial length for flow to develop before exiting the domewall 490.

FIG. 12 is a schematic of a first set of dilution openings 592 located,by way of non-limiting example in the region IV of FIG. 3 of combustor80. The first set of dilution openings 592 are substantially similar tothe first set of dilution openings 92, therefore, like parts will beidentified with like numerals increased by 500. It should be understoodthat the description of the like parts of the first set of dilutionopenings 92 applies to the first set of dilution openings 592 unlessotherwise noted.

A dome wall 590 can include a deflector 530 and an impingement wall 558spaced apart to define an intermediate plenum 560. The first set ofdilution openings 592 can include, by way of non-limiting example twodilution openings radially disposed within the dome wall 590. The firstset of dilution openings 592 can be defined at least in part by an axialflow vane 520 a extending between a dilution inlet 522 at theimpingement wall 558 and a dilution outlet 524 at the deflector 530.

A third set of dilution openings 546 can be located around a flare cone604. The third set of dilution openings 546 can include a purge passage548 extending between a purge inlet 550 and a purge outlet 552. An inletplenum 554 can be fluidly coupled to the first set of dilution openings592 and the purge passage 548 at the purge inlet 550.

A set of impingement holes 562 can be located in the impingement wall558 surrounding the dilution inlets 522 of the first set of dilutionopenings 592. The impingement holes 562 can exhaust into the impingementplenum 560 for impingement onto an inner surface 564 of the deflector530.

A set of film cooling holes 566 can be located in the deflector 530. Theset of film cooling holes 566 can fluidly couple the impingement plenum560 to an exterior surface 568 of the deflector 530. It is furthercontemplated that the set of film cooling holes fluidly couple one of ora combination of the inlet plenum 554, impingement plenum 560, or thefirst set of dilution openings 592 to the exterior surface 568.

It should be understood that while the cross-sectional view illustratedshows all the holes/openings in the same plane, each of theholes/openings can be distributed circumferentially about a fuel/airmixture outlet/dome inlet 596 in any suitable manner.

In addition to or along with the flow described previously herein,during operation compressed air (C) can pass through the set ofimpingement holes 562 and impinge onto the inner surface 564 of thedeflector 530 to define an impingement flow (I). Compressed air (C) canpass through the set of film cooling holes 566 and exhaust onto theexterior surface 568 to define a film cooling flow (FC).

Turning to FIG. 13 , illustrated is a schematic of an enlarged view of avariation of the flare cone 104 and dome wall 90 arrangement forcombustor 80 located in portion V of FIG. 3 , according to anotheraspect of the disclosure herein. A flare cone 704 and a dome wall 690are substantially similar to the flare cone 104 and dome wall 90 ofcombustor 80, therefore like parts will be identified with like numeralsincreased by 600. It should be understood that the description of thelike parts of the flare cone 104 and dome wall 90 applies to the flarecone 704 and the dome wall 690 unless otherwise noted.

The flare cone 704 can define a fuel/air mixture outlet/dome inlet 696.A third set of dilution openings 646, similar to the third set ofdilution openings previously described herein, can be located around theflare cone 704. The third set of dilution openings 646 can include apurge passage 648 extending between a purge inlet 650 and a purge outlet652 parallel to and proximate the flare cone 704. The purge passage 648can define a fourth centerline (CL4) angled away from fuel/air mixtureoutlet/dome inlet 696.

The third set of dilution openings 646 can further include a peripheraldilution passage 649 extending between a dilution inlet 651 and adilution outlet 653 radially outward the purge passage 648. Theperipheral passage 649 can define a fifth dilution centerline (CL5)angled away from the fuel/air mixture outlet/dome inlet 696. The fourthand fifth dilution centerlines (CL4, CL5) can be parallel to each other,or within 20% of parallel to each other. An inlet plenum 654 can befluidly coupled to the third set of dilution openings 646 at the inlets650, 651.

Turning to FIG. 14 , illustrated is a schematic of an enlarged view of avariation of the flare cone 104 and dome wall 90 arrangement forcombustor 80 located in portion V of FIG. 3 , according to anotheraspect of the disclosure herein. A flare cone 804 and a dome wall 790are substantially similar to the flare cone 104 and dome wall 90 ofcombustor 80 of FIG. 3 , therefore like parts will be identified withlike numerals increased by 700. It should be understood that thedescription of the like parts of the flare cone 104 and dome wall 90applies to the flare cone 804 and the dome wall 790 unless otherwisenoted.

The flare cone 804 can define a fuel/air mixture outlet/dome inlet 796.A third set of dilution openings 746, similar to the third set ofdilution openings previously described herein, can be located around theflare cone 804. The third set of dilution openings 746 can include apurge passage 748 extending between a purge inlet 750 and a purge outlet752 parallel to and proximate the flare cone 804. The purge passage 748can define a sixth dilution centerline (CL6) angled in a firstdirection, illustrated with arrow 701 toward the flare cone 804 and thenangled in a second direction illustrated with arrow 702 away from theflare cone 804. An inlet plenum 754 can be fluidly coupled to the thirdset of dilution openings 746 at the purge inlets 750. During operationcompressed air (C) can flow through the third set of dilution openings746 to first form an impingement flow (I). The impingement flow (I) canturn away from the fuel/air mixture outlet/dome inlet 796 and exhaustthrough the outlet 752 as a purged airflow (P).

Turning to FIG. 15 a variation of a portion of the cross-section view ofa combustion section 70 within the gas turbine engine 10 is illustrated.In this variation the first set of dilution openings 92 can be segmenteddilution openings, where the first set of dilution openings 92 arecircumferentially disposed around the engine centerline 21 within thedome wall 90 in a segmented annulus as illustrated. Therefore, the vanesas described herein can also be disposed around the engine centerline 21in a segmented arrangement.

FIG. 16 is a cross-sectional view of a combustion section 370, avariation of the combustion section 70 of FIG. 15 , illustrating anarrangement of dome walls 390 about an engine centerline 321. Each ofthe dome walls described hereafter can include discrete dilutionopenings arranged about the engine centerline 321. This is a variationof the annular dilution openings illustrated in FIG. 2 .

FIG. 17 is an exemplary distribution for the set of dilution openings492 described herein and located within the dome wall 490 similarly tothe arrangement in FIG. 16 . While the first set of dilution openings492 is numerically indicated, it should be understood that any of thesets of dilution openings described herein arranged in a circumferentialarray about the fuel/air mixture outlet/dome inlet 496 is contemplated.

FIG. 18 is a second exemplary distribution for the set of dilutionopenings 392 described herein and located within the dome wall 390 asarranged in FIG. 16 . While the first set of dilution openings 392 isnumerically indicated, it should be understood that any of the sets ofdilution openings described herein arranged about the fuel/air mixtureoutlet/dome inlet 396 is contemplated. In this particular arrangement,dilution openings are provided in corners 393 of the dome wall 390.

FIG. 19 is an exemplary distribution for the set of dilution openings392 described herein and located within the dome wall 390 as arranged inFIG. 16 . While the first set of dilution openings 392 is numericallyindicated, it should be understood that any of the sets of dilutionopenings described herein arranged annularly about a fuel/air mixtureoutlet/dome inlet 396 for flame shaping and to prevent high temperatureon the combustor liner 82 (FIG. 3 ).

FIG. 20 is a third exemplary distribution for the set of dilutionopenings 392 described herein and located within the dome wall 390 asarranged in FIG. 16 . While the first set of dilution openings 392 isnumerically indicated, it should be understood that any of the sets ofdilution openings described herein arranged about the fuel/air mixtureoutlet/dome inlet 396 is contemplated. In this particular arrangement,the dilution openings are slotted openings. The slotted openings canhave any shape by way of non-limiting example race track, circular, orelliptical. Further the slotted openings can be oriented in any suitablemanner by way of non-limiting example angled with respect to the radialdirection as illustrated.

FIG. 21 is a fourth exemplary distribution for the set of dilutionopenings 392 described herein and located within the dome wall 390 asarranged in FIG. 16 . While the first set of dilution openings 392 isnumerically indicated, it should be understood that any of the sets ofdilution openings described herein arranged about the fuel/air mixtureoutlet/dome inlet 396 is contemplated. The set of dilution openings 392can be annular about the dome centerline (DC). In this particulararrangement, the set of dilution openings 392 are annular slottedopenings arranged annularly about the fuel/air mixture outlet/dome inlet396.

Any combination of the exemplary dome walls and variations of thedilution openings locations described herein are contemplated. FIGS.4-21 are for illustrative purposes only and not meant to be limiting.The dilution holes/slotted openings can be in any form described herein.The deflector as described herein can be fed directly from under cowlregion or implement a double pressure drop design. The compressed air asdescribed herein can be a dilution flow with swirl that is generated byaxial/radial flow vanes as described herein. It should be understoodthat the dilution flow as described herein can be arranged about aswirler axis or an engine axis. Each exemplary arrangement produces adilution flow that is directed to keep hot gases away from the deflectorand combustor liner by pushing hot gases away from walls such thatmixing occurs away from the wall. The deflector as described herein canbe cooled by back-side or film cooling or both.

It should be appreciated that the dilution openings as described hereinare exemplary as illustrated. The dilution openings can be organized ina myriad of different ways, and can include by way of non-limitingexample ribs, pin banks, circuits, sub-circuits, film-openings, plenums,mesh, and turbulators, of any shape or size. The dilution openings caninclude other flow enhancing devices, by way of non-limiting example asmall opening located behind the dilution opening. It is furthercontemplated that the dilution openings can be part of a collection ofdilution openings. It is also contemplated that the dilution openingscan be in addition to and separate from a collection of cooling openingslocated along the combustor liner.

A method for controlling nitrogen oxides, or NOR present in combustiongases (G) within the combustor 80, includes injecting the dilutionairflow (D) into the combustion chamber as described herein through thedilution openings located in the dome walls described herein at theangles described herein. The method can further includes injecting apurge flow (P) into the combustor as described herein.

Benefits associated with the combustor liner and methods describedherein are uniform temperature distribution downstream of dilutionopenings which equates with better NOR and combustor exit temperatureprofile/pattern. A lower temperature on the deflector and liner equatewith a better liner and deflector life. Further the dilution openingarrangements described herein enable control of the flame structurewithin the combustion chamber.

While described with respect to a gas turbine engine, it should beappreciated that the combustor as described herein can be for any enginewith a having a combustor that emits NOR. It should be appreciated thatapplication of aspects of the disclosure discussed herein are applicableto engines with propeller sections or fan and booster sections alongwith turbojets and turbo engines as well.

To the extent not already described, the different features andstructures of the various embodiments can be used in combination, or insubstitution with each other as desired. That one feature is notillustrated in all of the embodiments is not meant to be construed thatit cannot be so illustrated, but is done for brevity of description.Thus, the various features of the different embodiments can be mixed andmatched as desired to form new embodiments, whether or not the newembodiments are expressly described. All combinations or permutations offeatures described herein are covered by this disclosure.

This written description uses examples to describe aspects of thedisclosure described herein, including the best mode, and also to enableany person skilled in the art to practice aspects of the disclosure,including making and using any devices or systems and performing anyincorporated methods. The patentable scope of aspects of the disclosureis defined by the claims, and may include other examples that occur tothose skilled in the art. Such other examples are intended to be withinthe scope of the claims if they have structural elements that do notdiffer from the literal language of the claims, or if they includeequivalent structural elements with insubstantial differences from theliteral languages of the claims.

Further aspects are provided by the subject matter of the followingclauses:

A gas turbine engine comprising a compressor section and a combustionsection in serial flow arrangement along an engine centerline, thecombustion section comprising a combustor liner; a dome wall coupled tothe combustor liner, and a dome inlet located in the dome wall; a fuelinjector fluidly coupled to the dome inlet; a combustion chamber fluidlycoupled to the fuel injector and defined at least in part by thecombustor liner and the dome wall; and at least one set of dilutionopenings located in the dome wall and fluidly coupled to the combustionchamber, the at least one set of dilution openings circumferentiallyarranged about the engine centerline.

The gas turbine engine of any preceding clause, wherein the at least oneset of dilution openings is a first set of dilution openings and asecond set of dilution openings concentric with respect to each other.

The gas turbine engine of any preceding clause, wherein at least one ofthe first and second set of dilution openings are annular dilutionopenings.

The gas turbine engine of any preceding clause, wherein at least one ofthe first and second set of dilution openings are segmented dilutionopenings.

The gas turbine engine of any preceding clause, wherein the at least oneset of dilution openings extends between a dilution inlet and a dilutionoutlet at the dome wall.

The gas turbine engine of any preceding clause, further comprising atleast one vane disposed within the at least one set of dilution openingsbetween the dilution inlet and the dilution outlet.

The gas turbine engine of any preceding clause, wherein the at least onevane is one of a radial flow vane or an axial flow vane.

The gas turbine engine of any preceding clause, wherein the dome inletdefines a dome centerline and the at least one set of dilution openingsdefines a dilution centerline.

The gas turbine engine of any preceding clause, wherein the dilutioncenterline is a first centerline angled toward the longitudinal axis andintersecting with the dome centerline to define a dilution angle.

The gas turbine engine of any preceding clause, wherein the dome walldefines a conic portion forming an obtuse angle with the combustor linerand the dome wall extends radially between the fuel injector and thecombustor liner to define a flat portion, wherein the flat portion andthe conic portion meet at a first junction.

The gas turbine engine of any preceding clause, wherein the at least oneset of dilution openings is located in the conic portion.

The gas turbine engine of any preceding clause, wherein the conicportion extends between the first junction and the combustor liner.

The gas turbine engine of any preceding clause, wherein the at least oneset of dilution openings is located in the flat portion.

The gas turbine engine of any preceding clause, wherein the flat portionextends between the first junction and the combustor liner.

The gas turbine engine of any preceding clause, further comprising aflare cone disposed around the fuel injector, wherein the flare conemeets the flat portion at a second junction and wherein the flat portionextends between the first junction and the second junction.

The gas turbine engine of any preceding clause, further comprising aflare cone disposed around the fuel injector, wherein the flare conemeets the conic portion at a second junction and wherein the conicportion extends between the first junction and the second junction.

The gas turbine engine of any preceding clause, further comprising aflare cone disposed around the fuel injector and a purge passagedisposed around the flare cone.

The gas turbine engine of any preceding clause, further comprising atleast one axial deflector.

The gas turbine engine of any preceding clause, wherein the dome wallcomprises a deflector and an impingement wall spaced apart to define anintermediate plenum.

The gas turbine engine of any preceding clause, wherein the at least oneset of dilution openings are circumferentially disposed about the domeinlet.

1. A gas turbine engine comprising: a compressor section and acombustion section in serial flow arrangement along an enginecenterline, the combustion section comprising: a combustor liner; a domewall coupled to the combustor liner, and a dome inlet located in thedome wall, wherein the dome wall defines a conic portion forming anobtuse angle with the combustor liner; a fuel injector fluidly coupledto the dome inlet, wherein the dome wall extends radially between thefuel injector and the combustor liner to define a flat portion, whereinthe flat portion and the conic portion meet at a first junction; a flarecone disposed around the fuel injector, wherein the flare cone meets theconic portion at a second junction and wherein the conic portion extendsbetween the first junction and the second junction; a combustion chamberfluidly coupled to the fuel injector and defined at least in part by thecombustor liner and the dome wall; and at least one set of dilutionopenings located in the dome wall and fluidly coupled to the combustionchamber, the at least one set of dilution openings circumferentiallyarranged about the engine centerline; wherein the at least one set ofdilution openings forms one of a segmented annulus about a circumferenceof the engine centerline or an annulus about the circumference of theengine centerline.
 2. The gas turbine engine of claim 1 wherein the atleast one set of dilution openings is a first set of dilution openingsand a second set of dilution openings concentric with respect to eachother.
 3. The gas turbine engine of claim 2 wherein the first set ofdilution openings forms the annulus and the second set of dilutionopenings forms a second annulus about the circumference of the enginecenterline.
 4. The gas turbine engine of claim 2 wherein both the firstand second set of dilution openings are segmented dilution openingsdefining the segmented annulus.
 5. The gas turbine engine of claim 1wherein the at least one set of dilution openings extends between adilution inlet and a dilution outlet at the dome wall.
 6. The gasturbine engine of claim 5, further comprising at least one vane disposedwithin the at least one set of dilution openings between the dilutioninlet and the dilution outlet.
 7. The gas turbine engine of claim 6where in the at least one vane is one of a radial flow vane or an axialflow vane.
 8. The gas turbine engine of claim 1 wherein the dome inletdefines a dome centerline and the at least one set of dilution openingsdefines a dilution centerline.
 9. The gas turbine engine of claim 8wherein the dilution centerline is a first centerline angled toward alongitudinal axis and intersecting with the dome centerline to define adilution angle.
 10. (canceled)
 11. The gas turbine engine of claim 1wherein the at least one set of dilution openings is located in theconic portion.
 12. The gas turbine engine of claim 11 wherein the conicportion extends between the first junction and the combustor liner. 13.The gas turbine engine of claim 1 wherein the at least one set ofdilution openings is located in the flat portion.
 14. The gas turbineengine of claim 13 wherein the flat portion extends between the firstjunction and the combustor liner.
 15. The gas turbine engine of claim 1further comprising a flare cone disposed around the fuel injector,wherein the flare cone meets the flat portion at a second junction andwherein the flat portion extends between the first junction and thesecond junction.
 16. (canceled)
 17. The gas turbine engine of claim 1further comprising a flare cone disposed around the fuel injector and apurge passage disposed around the flare cone.
 18. The gas turbine engineof claim 1 further comprising at least one axial deflector.
 19. The gasturbine engine of claim 1 wherein the dome wall comprises a deflectorand an impingement wall spaced apart to define an intermediate plenum.20. The gas turbine engine of claim 1 wherein the at least one set ofdilution openings are circumferentially disposed about the dome inlet.21. A gas turbine engine comprising: a compressor section and acombustion section in serial flow arrangement along an enginecenterline, the combustion section comprising: a combustor liner; a domewall defining a conic portion and coupled to the combustor liner,wherein the conic portion forms an obtuse angle with the combustorliner; a dome inlet located in the dome wall; a fuel injector fluidlycoupled to the dome inlet, wherein the dome wall extends radiallybetween the fuel injector and the combustor liner to define a flatportion, and wherein the flat portion and the conic portion meet at afirst junction; a flare cone disposed around the fuel injector, whereinthe flare cone meets the conic portion at a second junction, and whereinthe conic portion extends between the first junction and the secondjunction. a combustion chamber fluidly coupled to the fuel injector anddefined at least in part by the combustor liner and the dome wall; andat least one set of dilution openings located in the dome wall andfluidly coupled to the combustion chamber.
 22. The gas turbine engine ofclaim 21 wherein, the at least one set of dilution openings arecircumferentially arranged about the engine centerline forming one of asegmented annulus about a circumference of the engine centerline or anannulus about the circumference of the engine centerline.